TOPIC: 1998 Toyota Camry 2.2L 4 Cylinder

Ask Tracy but I dont think you have to recut it, just take off the "scalloped ridge" between cuts.
Just be careful as to not overdue it like I did. Tracy or Dan can be the authority here on your next move with this. Rough but effective is better than my groove that was polished and too wide.
Unless they think your groove is too far away from the throttle plate to get the best results.

Nate, before you do anything- how does it run as is? Any change to power anywhere in the driving range? Did you try sniffing the tailpipe before/after? MPG- the SG is useful but its the math at the pump tells overall story.

If you feel it's lacking in improvements- then I would first advise using a vice w/ plastic jaws or a rag or even cardboard to protect TB. Find a good position to work in. Take your time. I like my Panavice a lot for Grooving. Setup your work place to be convienient.

IF your bit fits tightly in the large section of each cut with little wobble then that fit is the guide. You need to only remove as much of those scallop ridges as is possible without wallowing out the cross-section. It's prob. better to cautiously bring those ridges down most of the way, you will have to judge the fit as you go. Perfect is the enemy of good enough. I'd also advise using both hands on the Dremel, you will find the right way for you.

Holding that Dremel steady will be a challenge, need to focus intently. Tell youself to stop, cool the bit, then remove it and check your bit fit OFTEN. At least your bits are new so should cut well. IT may cut faster than you think, look at this as "shaving" not "cutting". The most important area is the middle third of the Groove. So start at an end and try there first. If you get positioned so the TB is clamped in place where you're sitting down and it's closer to lap-height instead of higher to your torso, you might find you have better use of hand/arm stregnth to control the bit. And you could re-position the TB several times so you are always working in a more level plane instead of trying to follow the bore radius upwards. Play around with all positions to find the one that gives best control.

Overall just do your best to remove those ridges, but it's EASY to go too far! Remove as much ridge height without penciling or wallowing as you feel possible. IT will prob. come out kinda rough, just concentrate on bit-fit!

Good Luck, Commander Nate- should you accept this Mission....
"this tape will self-destruct in five seconds..."

Don't worry 'bout it, hey the Sun will come up tomorrow anyway!!


The results of this will be very useful info, Nate. Please do take more of your excellent pics if possible as you do it. If you can define for us all what the before/after driving, MPG, ect. is like, then it will be like Ron is here teaching us IMHO! Here's a pic of my Panavice.

Tracy G

Tracy,

I'm not quite done learning what this groove has to teach me so I won't be making any changes just yet. When I finished cutting the groove I looked and it and thought to myself…… hmmm this doesn't look right. I put a lot of attention into making sure that all my angles where correct and that my downward cutting motion was straight down. I didn't put enough attention into the spacing of the cuts.

I used a vise to hold the TB and two hands on the dremel, along with foot pedal speed control while standing. The vise has a vacuum base, the vac base was useless at the time so I taped the vice down (didn't work so great). This was a large part of the reason why I couldn't remove the the scallops. I figured if I tried to remove them with the technique I was using I would mess up the cuts I already made. I figured the bit would easily jump into the adjacent cuts instead of staying in the center on of ridges. Even with the foot control I was having some issues when starting each cut but it got better towards the end.

I cooled the bit in water after each cut. I heard a sizzle a few times.

So after completing the cuts and realizing what happened, I had the choice of fill and recut or put the tb on the car. By that time I was pretty tired and decided to put it on the car, accepting that this groove may not even work which was perfectly okay. The groove is connected but not by very much. I figured it would do SOMETHING, maybe work, maybe cause a problem, etc. I goal of this groove was never a "perfect groove", infact I'm not sure what I cut even is the "groove" but it is most defiantly a learning experience.


OK so about the performance of the groove. I'll do my best to describe it.

Side note: I have reset the ecu a bunch of times because of another project I was working on so I haven't really given the ecu time to really do some long term adaptive learning.

The groove works but it has a VERY narrow working range. I'm assuming this is true but I haven't experienced any other groove.

It works enough that it fits my driving style and the SG mpg is better when I'm not in that 19TPS sweet spot. My foot is still learning where 19TPS is, most of the time I land on 18TPS, increase throttle pressure a tiny amount, wait long enough for the SG to update, if SG still reads 18 I increase throttle pressure again and usually the SG will read 19 TPS. Sometimes I need to increase throttle pressure again to hit 19. Once it hits 19 the car will continue to slowly accelerate to a speed I'm not sure of (I stopped testing at 60 or so on a flat road). At 19 the map pressure drops, it will raise a bit after the automatic transmission shifts but the vacuum will start to drop again. It also feels like there is less engine resistance in a way. The tiny throttle pressure increases to get from 18-19 may be moving the ecu into a different area of the map but I'm not really sure what is happening.

I did notice a type of light surge when I first tested the groove. I haven't tried to find it in awhile. It seemed more like something was on the edge of going into resonance. I don't open the throttle past 19 when I don't need to and I think this one happens around 22 or so.

I did a test drive while keeping the throttle at 19 as much as possible for about 15 miles. The test drive after that run I drove normally, not really paying attention to the SG MPG/AVG and when I got close to home I looked at the SG and saw the largest AVG so far.

Edit: Forgot to mention, At 19TPS the car is accelerating and gaining MPG on the SG

Well what did I say- you ARE showing us things Nate, in more ways than one!

OK so is there an increase in torque at 19TPS, does the car just want to keep going at that sweet spot? Cause looking again at those super-sharp pics at 19TPS where the blade is engaged w/ the Groove you can see the air can enter through the flat area of Groove, go round the plate and come out through the rounded bottom of the scallop cuts. Very interesting- I think it's getting more airflow at 19TPS now than before the Groove. IT's like a series of small Grooves in a row. Perhaps the Groove effect is taking place just right at the round "top" of these "eyebrow" cuts. Thinking out loud here, never seen cuts like this before. Instead of a single tight vortex forming and pulsating out of the whole Groove, maybe a series of "spike" narrow vortexes form- one out of the bottom of each scallop.

Maybe right now it's a combo of extra airflow plus the very narrow vortex spikes at 19TPS. And yes it makes sense this would be very "peaky" only around this TPS angle. IF the scallop cut ridges were'nt there, you might have both more airflow at a lower TPS angle, AND the whole, single, Groove rolling annular vortex could form and manifest the stronger effect. Increase in airflow and the Groove vortex "half-a smokering" would come in at an earlier lesser throttle angle, and that should give a torque increase. MPG could also increae, as well, since more power comes on at less total TPS. Long as your foot stays out of it anyway.

Nate since you are already pretty far up the learning curve, I'll share a couple advanced ideas here. There is a Gadgetman, Mike Hollar, Ron spent some time w/ Mike 2 years ago. I won't go into much detail here, but Mike Hollar is a "guru" of engine mods. He's been involved in MANY advanced programs, the Gadgetman Groove being just one. Mike made a suggestion then of gently radiusing the "leading edge"- the flat bottom of the Groove- so that as air comes down the throttle bore wall it has an easier path into the Groove. Meaning, just gently sand or carefully file that sharp edge at the upstream air filter edge where the flat bottom of the Groove intersects the bore wall. Just lightly break the edge, even a small piece of sandpaper could work. Don't try to remove material, just very lightly break the leading edge. This should in theory increase the laminar airflow into the Groove cavity. I'd leave the exit downstream Groove edges alone except to remove any burrs that get raised.

Second is throttle plate shaping. Tacoma Karl did a good graphic of this here:



Ron also did a video of this on a DBW Chevy Vortec TB at Aaron Cheek's place in Nebraska 2 yrs ago. IT should be in the You Tube Groovy Service Bulletins channel on youtube. It's pretty easy to do on big thick throttle blades like those Vortec's. Tougher to do on a smaller thinner one. On a brass blade like yours Nate, heck maybe even a girl's emery nail board might do it, followed by fine sandpaper to smooth. Might only be able to to the middle 2/3 of the downstream edge of the blade. But worth trying to me anyhow.

wow you have a foot pedal for your Dremel? Jealous here!

A good vice or Panavice is what you need next.

Keep goin'!

Tracy G

It's hard to say if there is an increase in torque based of feel alone.

I did read in the training manual about removing the burrs but forgot to do it.

In the WOT picture I noticed not only the burrs but a misaligntment between the throttle body and the intake manifold.



I removed the throttle body to get rid of the burrs and took more pictures of the groove from a different angle.





Did a better job aligning the TB before torquing it down.


I plan on doing the throttle plate shaping but not until I have a "final version" groove.

Well Nate, I gotta say, that Is one choppy Groove you got there! I think the 2 things for you to remember are- get a suitable vice w/ a way to protect the TB from vice damage, and next time remember to do the move to the Left w/ the bit after it hits full depth. Always overlap your cuts by a half bit width. 2 or 3 times the # of cuts you did here, along w. the above suggestions, and you will be getting it much better.


So if you are seeing some improvements via scanguage--and if seat of the pants is improved at all- and if the tailpipe has cleaned up any-

Well then you just joined the Caveman Club!! Hey I'm a charter Member, pull up a rock, let's swap Caveman Groove stories!! Hey, there's no Sculptors or Artists in here, we're Caveman Groovers!

Tracy G

Let me pull up a rock.

So is it possible to recut this throttle body? Would I need to fill in the teeth marks first with JB or should I try to make some additional cuts to the TB? Any tips on groove filling with JB?

Sure It's possible to clean this Groove job up. The flat base part stairsteps up/down visibly so I think it would e best to attempt to just knock down the ridges between cuts. Don't try to make it pretty, if you do it will wallow out too much. Also don't try to even out the "elevation" of the base of the cuts relative to the plate. Clamp this TB in a vise where you will have strong control position of the Dremel whether you sit or stand. Positioning it so it relatively lower in relation to you can give better Dremel control. But experiment w/ position a lot, I think that's a lot of what happened here. First I'd just try to connect the cuts. And check the bit goes full depth. It's going to wind up w/ the flat base of Groove snaking up/ down relative to plate as that's how it was cut. You can just try to remove the ridges, look at it closely judging angles very carefully. I'd do a visual alignment with whatever works for you visually as a guide. Work on the ouboard edge cuts first to get an idea of how the tool will behave try the right to left motion first. Just try it- if you are real unhappy w/ results it can be filled in w/ JB weld and try again. But- if you do this and re-cut using large bit could wind up w/ thin sections of epoxy, med. bit would leave more epoxy in place. Reg. Jb weld setus up harder stronger than JB Quick, though Ron always seemed happy w/ it.

Tracy G

It looks like I need to explain alittle on cutting the groove, I hold the throttle body in my left hand and dremel tool in right start from left and dig down close to end of stem,dont bury the bit untill you get a fourth of groove across then bring it right to left back in one full swipe all the way to stem, it will be uniforn smooth deep groove, then do the next fourth untill you have it all done the groove will look like a factory cut,dont get in a hurry let the bit do the work it looks like most on forum are forcing the bit to much adjust speed as to not let bit to get to hot. this will become as easy as writing your name with practice and bits will last longer. When you get done cutting the groove take the bit out of dremel and it will lay in groove perfect all the way around without you holding bit and there you will notice the angle you have cut per degree. after the groove is cut I blow out all shavings before cleaning with any throttlebody cleaner, this seems to clean better and use alot less cleaner. always emory cloth the edges of groove as to make sure no burrs have risen to touch butterfly as it could cause a check engine light or limp mode code. Happy Grooving Dan

Thanks Dan.

That's the voice of Experience folks!

Tracy G

Awesome, ok so I have some things to try. I'm not quite done with this cut yet but when I am I think I will attempt to make this a continuous groove.

Nate I just looked on ebay and found this:http://www.ebay.com/itm/97-98-99-00-TOYOTA-CAMRY-THROTTLE-BODY-4-CYL-5SFE-ENG-FED-/181121164864?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A1998%7CMake%3AToyota%7CModel%3ACamry%7CEngine+-+Liter_Display%3A2.2L&hash=item2a2ba9a640&vxp=mtr#ht_2400wt_998

Hope that link works, a cheap used TB think it's right one for your Camry. Well now I see it's not a real link! On ebay auto parts section simply searched '98 Toyota Camry 2/2L throttle body. Very cheap right this moment. So just to show, it can be possible to find replacement TB's if you look. Spent 4 min. finding this one. So a back up TB is an option if ya want. I'm glad Dan chimed in w/ his tech tip, I'm going to use it now. that's what the forum is for!

Tracy G